[78Survivor]

Let me start by saying I’m new to Pontiac and the proud owner of a blown apart 78 Firebird.

My intended use for the car is power tour, cross country road trip car drag week car. It needs to be able to do 500 miles or so a day for a week straight then Friday night cruise with the wife and kids to Dairy Queen.

Here is what I’m working with: 3.23 rear, factory 3 speed auto, W72 engine with 6x4 heads , installing stock 72 manifold in favor or air cleaner and shaker hood, oe 800 cfm Rochester to retain factory look, linkage and reliability and possibly reinstall the cruise control.

I would like to upgrade the cam from stock but retain the stock items above. I’m looking for hydraulic flat tappet suggestions only not looking to do a roller set up. What are the best choices what lifters are the best quality and least likely to have failure issues.

Thank you in advance for your help and suggestions.

This is what I’m shooting for visually:

[78Survivor]

I’m leaning towards the melling spc-7 cam

[roger1]

I'm having my '69 400 put together right now at a machine shop with a new Lunati Voodoo 10510702 kit. It also has new KB dished pistons that should give it about 9 to 9.5 to 1 compression. They are going to put it on their dyno so I will be able to see what it makes. Should be in the next week or 2.

[steve25]

Ok, so let’s nail down some added and needed details here!
Can we assume your staying with a 400 cid motor and just going to bore it .030” over, if so then those 6X-4 heads will give you a compression of only 8.5 if you do not mill them.

The 7 cam would work ok with your 3.23 gears if you get the compression up to 9.5 , but you should really step into a more modern Cam with more lift, like in the .470” to .490” range.
Utilizing lift in this range will add bunch more torque to the motor besides added more hp.

Either way the rocket studs need to be up graded from the stock 3/8” bottle neck along with a set of poly locks for adjustment.

Your stock springs either way on the heads will need to go and the heads need to cut for positive valve seals and new valves should be seriously consider also.

A HD oil pump driveshaft should be on your parts list also, your pump may be reusable if it checks out good?

[78Survivor]

Originally Posted by steve25

Ok, so let’s nail down some added and needed details here!
Can we assume your staying with a 400 cid motor ....yes


and just going to bore it .030” over....don’t know just refreshing an unknown motor to my desired specs/intended use



, if so then those 6X-4 heads will give you a compression of only 8.5 if you do not mill them.... they may have been milled already, don’t know

The 7 cam would work ok with your 3.23 gears if you get the compression up to 9.5 , but you should really step into a more modern Cam with more lift, like in the .470” to .490” range.
Utilizing lift in this range will add bunch more torque to the motor besides added more hp....thank you I will ponder what trade offs this creates

Either way the rocket studs need to be up graded from the stock 3/8” bottle neck along with a set of poly locks for adjustment.....you lost me here my knowledge is just enough to get me in trouble

Your stock springs either way on the heads will need to go and the heads need to cut for positive valve seals and new valves should be seriously consider also....I really was not looking for head work this was going to be a vice grip garage build. Check the mains and rod beatings, check the compression and drop in a fresh cam. The budget for reassembly is $2500 and I’m putting a completely blown apart car back together. Btw I know my budget will be blown by 100%

A HD oil pump driveshaft should be on your parts list also, your pump may be reusable if it checks out good?

....thanks I’ll order this up.

[Gary H]

If your rebuilding the engine anyway, I would go with Icon Pistons IC890 which come with 4.5 cc valve reliefs and will raise your compression ratio from it's current 8:1 to 9:1 if you zero deck the block. I'd go with the Lunati Vodoo 702 camshaft myself on a 114 LSA if your keeping the exhaust manifolds, 112 LSA if going with headers

[78Survivor]

Originally Posted by Gary H

If your rebuilding the engine anyway, I would go with Icon Pistons IC890 which come with 4.5 cc valve reliefs and will raise your compression ratio from it's current 8:1 to 9:1 if you zero deck the block. I'd go with the Lunati Vodoo 702 camshaft myself on a 114 LSA if your keeping the exhaust manifolds, 112 LSA if going with headers

This is not an engine rebuild. It is intended to be just a cam swap. Anything else will be just attending to must change parts. Rebuild may be in a couple years. For now is just put it together and have some fun. I did the deep dark rabbit hole on the corvette restoration this is a fun knock around friday night 20 footer

[b-man]

Easiest would be the SPC-7.

Same pushrod length and valve springs as it came equipped with from the factory, no additional valvetrain parts to buy. Of course a fresh set of stock replacement valve springs wouldn’t be a bad idea, but if yours are still in good shape it’s not absolutely necessary.

That cam which is more commonly known as the ‘068’ was used in a multitude of different performance applications ranging from the 330 hp ‘69 350 HO and 390 hp 428 HO all the way up to the ‘71-‘72 455 HO engines. It’s probably best known to most as the Tri-Power cam, from when it was used in the 360 hp ‘65 GTO 389 engines. It’s a pretty universal performance cam as evidenced by the multiple different displacements the Pontiac engineers chose to use it in.

None of the cars that were equipped with these engines were slouches and more than held their own out on the streets.

Yes it’s an old tech design with slower lifter action and a low lift at .407 with stock 1.5:1 rocker, and certainly slightly less because the factory rockers aren’t a true 1.5 and vary a little in actual ratio. You’re a lot less likely to wipe a cam lobe with the gentle action of the lobe profile, these were used in cars under warranty when they were new.

All in all it’s a great choice if you’re not into changing everything else in the valvetrain to suit a simple cam swap, I usually recommend it for these types of cam changes on otherwise stock engines.

[Formulas]

If your not adverse to a little noise at idle I would use Rhoads lifters to keep the torque up at first crack of the throttle, low compression, stock converter, 3.75 stroke motors with much of a camshaft at all get disappointing in a hurry

Pontiac never used the 068 in a 8.5 compression 3.75 stroke

.

[Cliff R]

Crower 60240. Its specs at 270/276, 210/221 @ .050" and /112LSA. Excellent cam for the later low compression 400 engines and the biggest cam that will work effectively with power brakes and other accessories and doesn't need a lot of rear gear either.

I've tried several other cams in those engines over the years and had several brought here to custom tune with aftermarket cams in them. The Comp XE262 is a "turd" in that application. Had several brought here, "quirky" idle quality and nothing impressive for power anyplace. Also had one come in with a Summit 2801 cam. It was "weak" at low RPM's and needed at least a full point more compression to work well, IMHO. Also had a poor soul roll in here with a later T/A that had the SPC-8 cam in his. I cranked over 50 degrees timing into it at idle speed and it still didn't make enough vacuum for brakes or idle well at all!

I had a 400 in the Ventura back in the 1980's, TH400, stock converter, 2.73 gears. It was topped with 6X heads and used the 60240 cam. Great power, good street manners and ran 14.0's at the track around 99-100mph. Best ever 13.87 @ 101mph.......Cliff

[78Survivor]

Perfect!

This is what i was looking for. I want a pepped up otherwise stock car with an oe look on a budget.

Thanks all!